Electromagnet



F. E. WARD.

ELECTROMAGNET. I APPLICATION FILED. JUNE 1, I921- 1,436,327. Patented Nov. 21, 1922.

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. B @441 7% Z? Alzt'omey Patented Nov. 21, 1922.

UNITED STATES PATENT OFFICE.

FREDERICK ELLIS WARD, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO CROCKER- WHEELER COMPANY, OF AMPERE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTROMAGNET.

Application filed June 1, 1921.

To all whom it may concern.-

Be it known that I, FREDERICK ELLIs WARD, a citizen of the United States of America, and a resident of East Orange, State of New Jersey, with a post-0fli0e address box 57, Ampere, New Jersey, have invented certain new and useful Improvements in Electromagnets, of which the following is a specification.

This invention relates particularly to a signal to be used in conjunction with a switch in an electric circuit, and its purpose is to show when the current in the leads rises to a point which is dangerous if continued, or to a point which requires a change in the switch connections as in starting a motor. One object of the invention is to provide an electromagnet for such a signal which will be simple to manufacture, will operate with alternating current, and capable of adjustment or construction for operation with any desired rise of current through a wide range.

In the accompanying sheet of drawings which forms a part of this application- Figure 1 is a vertical longitudinal section through an electric signal which embodies this invention.

Fig. 2 is a perspective of the magnetizable bar, armature and signal with the support therefor broken away.

Fig. 3 is a front view of the signal.

Fig. 4 is a side View of a portion of the signal including the coil.

A supporting plate 5 of insulating material supports through two studs 6, 7 a coiled conductor 8 with the axis of the coil perpendicular to the plate. There is a circular hole through the plate centered in the axis of the coil, and a tube 9 passes through the coil and hole. This tube is conveniently of fibre so that current will not circulate in it circumferentially. It is immaterial whether the tube is supported directly from the plate by being a fit in the hole or by the coil or by both. As shown it is supported by the plate. It carries at its front end a grid 10 with horizontal slots forming sight openings. A tang 11 in the edge of the grid engages a slot in the front end of the tube to prevent circular displacement, and 1t 1s covered by a sheet of transparent celluloid 12. Within the tube is carried a brass trough 13 with circular disks 14, 14 at its ends by which the trough is held'at the axis of the tube. A fixed magnetizable bar 15 is Serial No. 4mm.

held in the bottom of the trough by a bolt 16 and the tip of the bolt engages a slot in the rear end of the tube to prevent circu lar displacement of the signal with respect to the tube. A. second magnetizable bar 17 is carried by a transverse pin 18 which passes through the sides of the trough and serves as a fulcrum. This second bar is so placed that its rear end will overlap above the forward end of the other bar and will be normally spaced therefrom and will be an armature therefor. The point of overlap lies within the coil of the coiled conductor and the other ends of the bars extend in opposite directions from the point of overlap and in the direction of the axis of the coil. The bar which forms the movable armature is a lever fulcrumed midway of its ends and carries an arm 19 which is of iron so as to extend the magnetizable length. The arm carries a weight 20 which may be set at any point along the arm to standardize the sensitiveness at any given voltage and number of turns. The arm also carries a signal plate 21 with stripes painted thereon. The forward end of the armature bar is thus overbalanced and the rear end is normally spaced from the fixed bar and the painted stripes lie between and below the sight openings. A coil will be provided with such number of turns according to the current as will cause the signal to respond at the desired point in the rise of current. There is a distance rod 22 to limit the forward position of the signal in the tube and prevent the target from touching the grid.

When a suflicient current flows in the coil to sufficiently ma netize the two magnetizable bars the overI-apping end of the pivoted bar is attracted toward the other and the painted strips of the signal are brought in front of the sight openings.

I claim-- 1. In an electromagnet, a coiled conductor, and two relatively movable ma etizable bars disposed so as to overlap within the coil and extend in opposite directions in the direction of the axis of the coil from the point of overlap and so mounted that the overlapping ends are normally separated and will approach laterally when sufliciently magnetized, substantially as described.

2. In an electromagnet, a coiled conductor, a fixed magnetizable bar, and a movable magnetizable bar pivoted so as to be movable about an axis transverse to its length, the bars being disposed so as to overlap Within the coil and extend in opposite directions in the direction of the axis of the coil from the point of overlap, the movable bar being so mounted that it is normally spaced from the fixed bar and will approach laterally when suiiiciently magnetized, substantially as described.

3. In an electromagnet, a coiled conductor With a horizontal axis, a fixed lnagnetizable bar, and a movable magnetizable bar pivoted so as to be movable about an axis transverse to its length, the bars being disposed so as to overlap one above the other Within the coil and extend in opposite directions in the direction of the axis of the coil from the point of overlap, the movable bar being so mounted that it is normally spaced by gravity from the fixed bar and will approach Ver tically When sufficiently magnetized, substan tially as described at. In an electromagnet, a coiled conductor with a horizontal axis, a fixed magnetizable bar and a movable magnetizable bar pivoted so as to be movable about an axis transverse to its length and having one end overlapping above one end of the fixed bar and so Weighted that the overlapping ends will be normally spaced and Will approach vertically when sufficiently magnetized, the two bars being disposed so as to extend in opposite directions in the direction of the axis of the coiled conductor, from the point of overlap, substantially as described.

In an electromagnet, a coiled conductor, a tube Within the coiled conductor, a magnetizable bar and an armature for the bar Within the tube and supported therefrom and so mounted that they are normally spaced laterally and Will approach when sufliciently magnetized, substantially as described;

FREDERICK ELLIS NARI). 

